docs: def validate(self, **kwargs):
          r"""Validate record according to schema defined in ``$schema`` key.
  
          :Keyword Arguments:
            * **format_checker** --
              A ``format_checker`` is an instance of class
              :class:`jsonschema.FormatChecker` containing business logic to
              validate arbitrary formats. For example:
  
              >>> from jsonschema import FormatChecker
              >>> from jsonschema.validators import validate
              >>> checker = FormatChecker()
              >>> checker.checks('foo')(lambda el: el.startswith('foo'))
              <function <lambda> at ...>
              >>> validate('foo', {'format': 'foo'}, format_checker=checker)
  
              returns ``None``, which means that the validation was successful,
              while
  
              >>> validate('bar', {'format': 'foo'},
              ...    format_checker=checker)  # doctest: +IGNORE_EXCEPTION_DETAIL
              Traceback (most recent call last):
                ...
              ValidationError: 'bar' is not a 'foo'
                ...
  
              raises a :class:`jsonschema.exceptions.ValidationError`.
  
            * **validator** --
              A :class:`jsonschema.IValidator` class used for record validation.
              It will be used as `cls` argument when calling
              :func:`jsonschema.validate`. For example
  
              >>> from jsonschema.validators import extend, Draft4Validator
              >>> NoRequiredValidator = extend(
              ...     Draft4Validator,
              ...     validators={'required': lambda v, r, i, s: None}
              ... )
              >>> schema = {
              ...     'type': 'object',
              ...     'properties': {
              ...         'name': { 'type': 'string' },
              ...         'email': { 'type': 'string' },
              ...         'address': {'type': 'string' },
              ...         'telephone': { 'type': 'string' }
              ...     },
              ...     'required': ['name', 'email']
              ... }
              >>> from jsonschema.validators import validate
              >>> validate({}, schema, NoRequiredValidator)
  
              returns ``None``, which means that the validation was successful,
              while
  
              >>> validate({}, schema)  # doctest: +IGNORE_EXCEPTION_DETAIL
              Traceback (most recent call last):
              ...
              ValidationError: 'name' is a required property
              ...
  
              raises a :class:`jsonschema.exceptions.ValidationError`.
          """
          if '$schema' in self and self['$schema'] is not None:
              kwargs['cls'] = kwargs.pop('validator', None)
              _records_state.validate(self, self['$schema'], **kwargs)